On 9/18/26 9:47 AM, Yu Kuai wrote:
From: Yu Kuai<[email protected]>
blkcg_punt_bio_submit() currently queues punted bios on blkg->async_bios,
so it has to call bio_blkg() to find or create a queue-local blkg. Bios
now carry and pin the blkcg css, so punted bio lifetime no longer needs to
be anchored by a blkg.
Keeping the punt state in blkg can instantiate a blkg even when no blkcg
policy is enabled, just to bounce submission from a shared kthread. Move
async_bio_lock, async_bios and async_bio_work to struct blkcg, and queue
punted bios on bio_blkcg() for non-root cgroups. Root or unassociated bios
are submitted directly.
This preserves the priority-inversion avoidance while preventing
blkcg_punt_bio_submit() from creating blkgs that are not needed by any
policy.
Signed-off-by: Yu Kuai<[email protected]>
Looks good to me.
Reviewed-by: Nilay Shroff <[email protected]>
